An induction hob is a cooker hob that uses electromagnetic induction in the hob to heat a metal cooking pot. The heating is achieved by two different means:
- Magnetic hysteresis. The rapidly oscillating magnetic field causes power in the magnetic field to be converted to heat in the ferromagnetic base of the pot due to hysteresis. The amount of heat produced is proportional to the area of the hysteresis loop. This is primary source of heat in an induction hob.
- Eddy currents. The magnetic field also produces electric currents (known as eddy currents) in the metal base of the pot, and these cause resistive heating of the metal.
The heat from the pot is then transferred to the food by conduction.
An advantage of this system is that the electromagnet does not need to be in direct contact with the pot, so the hob can be sealed beneath a heat-resisting glass-ceramic sheet which is easily cleaned. Another feature is that the hob can heat only pots and pans that have a ferromagnetic bottom, and if left on accidentally will not burn nonmetals such as human skin.